An organic electroluminescent (hereinafter referred to as organic EL) panel is a light-emitting device that includes at least one organic EL element disposed on a supporting substrate, acts as a surface light source, and functions as, for example, an image display or an illuminating device. For example, in the organic EL element, a pair of electrodes including an anode and a cathode sandwiches an organic functional layer in which an organic light-emitting layer is held between a hole transport layer and an electrode transport layer, and any one of the electrodes is fixed on the supporting substrate such as a glass substrate and a resin substrate. In order to cause this organic EL element to emit light, current should be supplied through the electrode pair. For this reason, a connecting wire pair is disposed to selectively supply current to each organic EL element.
Use of the organic EL panel is not restricted to an image display. Even when the organic EL panel is used as an illuminating device, a plurality of organic EL elements are aligned in the organic EL panel in many cases. Therefore, it is general that a power supply line for supplying power from the outside to the connecting wire pair of each organic EL element is disposed on the substrate over a distribution region of the organic EL elements. In a case of an image display, the power supply line includes a plurality of horizontal line groups and vertical line groups that are crossed with the horizontal line groups, and each organic EL element is provided on each intersection of these line groups and serves as a pixel.
In the organic EL element, since the organic functional layer that is provided between the anode and the cathode has a thickness of submicron order, current leakage may be caused by fine dust or a defect of the organic functional layer. For example, when in the image display, current leakage occurs in one pixel, other pixels around the pixel may also be damaged.
As a technique for preventing damage of peripheral cells from spreading as described above, Patent Document 1 describes a procedure of blocking short-circuit current by providing a wire having a fuse function on each of a plurality of pixels. The fuse function causes melting disconnection by overcurrent during short circuit due to current leakage.
Patent Document 2 describes a technique of using a resin substrate and providing a silicon oxide film as a barrier layer against gas or the like on the resin substrate.
Patent Document 3 describes a technique of self-repairing a short circuit part by applying reverse bias voltage to electrodes to evaporate an electrode material.
Patent Document 4 discloses a technique of repairing a short circuit part by irradiating laser beam to the short circuit part, to melt and remove the short circuit part.